export JAVA_HOME=<PATH>

[oohwewubi]

How do I figure out <path>

[andrewc6l]

It depends which Java you have installed. If you have Sun Java 6 installed, it will be /usr/lib/jvm/java-6-sun/.

However, most Java implementations will run without JAVA_HOME set - are you sure you need it? (It will make your life harder if you decide to have multiple Java implementations installed.)

[kpkeerthi]

How do I figure out <path>

Find where Java is using

which java

Now do a long listing of the output from the above command
For e.g.

ls -l /usr/bin/java

It will usually be symlinked to /usr/lib/<blah> or /opt/<blah>/<blah>